Crown block



June 24, 1952 H. D. HILBORN ETAL CROWN BLOCK 2 SHEETS-SHEET l Fild April 19, 1947 .Illl

N n 0 E TBT mum V HW w. :1 DD .1 D m) wm mw ATTORNEY June 1952 H. D. Hl LBORN ET AL 2,601,511

CROWN BLOCK Filed April 19, 1947 2 SHEETSSHEET 2 INVENTORS HOWARD D. HILBORN 33 WILLIAM D. WALTERS ATTORNEY Patented June 24, 1952 UNITED STATES PATENT OFFICE CROWN BLOCK Howard D. Hilborn and William D. Walters, Houston, .Tex., .assignors to Emsco Derrick & Equipment Company, Los Angeles, Calif a corporation of California Application April 19, 1947, Serial No. 742,596

utilize load handling equipment of increased material strength. For example, larger cables are being utilized and sheaves of greater diameter, which introduce a serious problem from the standpoint of so disposing the load handling equipment that these increased load'forces will be property distributed. 1 a

More specifically, it becomes extremely important to I arrange the distribution of the sheaves constituting the crown block structure at. the top of a derrick or'mastso that load: .-forces. imposed upon associated traveling blocks and forces due to hoisting operations will be more symmetrically applied to the tower or derrick structure.

With the above in view, the present invention seeks to not only provide a crown block structure wherein thesheaves are so mounted that a.

symmetrical distribution of load forces may be obtained, but the crown block is more readily adapted for assembly and may, readily be modified to adapt it for a plurality of varied operations in the field, for example, different modes of reeving the hoisting cable.

It is therefore a primary object of theherein described invention to provide an improved crown block structure of the type wherein the fast-line is brought dOWn to a winding drum outside,,the derrick areas, as in the case of a mast or portable derrick; which has its sheaves soarranged as to enable leading the dead-line and fast-line portions of the hoisting cable into inner sheaves of the crown block and associated traveling block; which reduces fleet angleand provides better spooling of the hoisting cable, whereby wear on the cable and cable guides may be materially decreased; and in which distribution of the load forces is accomplished in a more symmetrical manner with respect to the derrick structure. I I

A further object is to provide animproved crown block structurehaving its sheaves so. arranged that increased fiexibility in reeving of the cable may be obtained, and the dead-line led out in a plurality of selective directions to permit variations of cable stringing and anchor 1ao1a ms. (oi. 254 1ss) positions to meet the varied requirements of different field personnel and methods of operation.

Still another object is to provide a crown block assembly of simple construction which may be readily adjusted in the field to compensate for derrick settling or other conditions, whereby the traveling block may be kept positioned over the center of the well.

Further objects of the invention will be brought out in the following part of the specification, wherein detailed description is for the purpose of fully disclosing preferred embodiments of the invention without placing limitations on the scope of the invention defined in the appended claims.

Referring to the drawings which are for illustrative purposes only:

Fig. 1 is a plan view of a crown block structure embodying the features of the present invention;

Fig. 2 is a fragmentary view of the upper end of an oil well derrick, showing a crown block structure according to the present invention mounted thereon, and its association with the usual traveling block; 7

Figs. 3 and 4 diagrammatically illustrate a1- ternate modes of stringing a hoisting cable between the crown block and traveling block to securealternate locations of the dead-line anchor; and

Figs. 5 and 6 respectively diagrammatically illustrate modified arrangements of the oil-set sheave, and other stringing arrangements in or- I der to locate the dead-line anchors at different desired locations.

As shown on the drawings, Fig. 2, the.nu-

I mcral Ill designates generally the upper part of a typical steel oil well derrick top which may be of conventional construction. This derrick top includes a water table II of substantially rectangular construction, being composed of spaced beams l2-l2 which are secured in spaced relation by means of lateral or side spacer channels t3 interconnected at their ends to connecting ribs 14' of the beams It. In this construction, the height of the beams l2 exceeds that of the spacer channels, so that the upper surfaces of the beams may serve as a support for a rigid box base structure M of the crown block assembly which will be now described.

The base structure M is fabricated from structural members which may be welded or otherwise secured together in conventional manbe supported as a unit on top of the water table.

More specifically the base structure includes a pair of spaced base beams l5-l 5 which are interconnected at their left ends as viewed in Figs. 1 and 2 by means of a pair of spacer beams IB-l 6 of approximately one-half the height of the base beams IS. The spacer beams provide a support for spaced apart cross beams I|-ll which have their uppermost surfaces lying in the plane of the upper surfaces of the base beams |5-l5, and serve as mountings for supporting bear.-.- ing brackets l8-|8 in which the respective. ends of a sheave shaft or pin IQ of an off-set sheave 2. are operatively associated.

Intermediate the ends of. the beams. l 5l5-,. there is rotatably mounted a plurality of sheaves 2Ia, 2lb, 2Ic, and 21d, these sheaves being mounted with their planes of rotation parallel. to that of the off-set sheave 2D and having a common axis of rotation with respect toa common sheave shaft or pin 22 having its ends supported. in brackets. 23-43 secured. to the upper surfaces of the edgewise positioned: beams |5'.|5..

"ltxwill: be. observed from Fig; 1 that the sheaves 21a and.2l1z are positioned together to: form. a group adjacent one endofthe shaft 22; whereas, sheaves 2Isc and 2|d are similarly positioned. to form a group adjacent. the other end ofthe. shaft 22.. Thus, adjacent inner sheaves 2th and. He are spacedapart a distance slightly greater than the. width ofthe ofL-set sheave. 20. with the plane of' rotation of the sheave. 20, when extended, passingmidway between. the sheaves 2 lb and: 21c. Moreover, it will 'be noted that diametrically opposed points of the off-set sheaveand the sheaves 21a. to 21 inclusive are adjacently disposed. That is, the right side of the groove. of.v the off-set. sheave 20. is substantially in alignment with the left side of. the grooves of the sheaves 2m to 2I-d.

At theT-other-ends ofv the beams l5'-l 5 there is provided a pair of spaced apart transversely extending channel members 24--24 having their uppermost surfaces lying in the same plane as the upper surfaces of thebeams l5--I'5. These channel members are positioned. edgewise and are. secured at their endsto the beams I i-l5, respectively,

and have interconnectingv ribs 252-5 forming a part ofthe end connections;

The channels 24-24 form a support for a cross-over sheave 28' supported with its plane of rotation at rightangl'es to the planes of rot'ationv off the other sheaves of the crown block upon a shaft or sheave pin 21 supportedat its respective ends by brackets 28'2B-positioned on the channel members 242 4. As thus mounted,

the center line of the shaft 21, if extended, passes between thesheaVes-Z I hand 2 1c and in the same plane as the central planeof rotation of the offset sheave 20'. It will be observed that the di-- ameter of the cross-over sheave--26 corresponds substantially to the distance between the outer faces of the sheaves 21a and 2ld.

Inthe arrangement described above, it will be observed that the left end ofthe base structure M; as viewed in Figs. 1 and 2, is mounted in overhanging relation to the adjacent side of the derrick sothat the shaft or pin l9 of'the oft-set sheave 20* is positioned substantially directly above the edge of the water table at this side. The support for the cross-over sheave 2B is centrally' positioned at the other side of' the water table, and the sheaves 2-'Ia--2 |d are symmetricallyarranged at the center of the water table. This gives a symmetrical arrangement so thata hoisting line 29 may rove over the sheaves of the crown block and through the sheaves of a traveling block 30 with a dead-line end portion 3i disposed or leading off within the derrick and a fast-line portion 32 carried over the off-set sheave and leading oif outside the derrick to the winding drum in suchaumanner' thatload forces will be morei'symmetrically and: equally distributed to the derrick structure.

The crown block assembly may be removably secured to the water table so as to permit shift ing of the crown block structure on the water table-to compensate for any settling of the derrick on other condition which might tend to 1 throwthe travellng block oif center of the derrick.

A further feature of the arrangment of sheaves in-. the crown block of my invention resides in the fact that with this construction it is possible to-mo'unt the sheaves with their axes of rotation lying sustantially in a. common plane. The surfaces. upon which. the: supporting; brackets for the. sheave shafts or pins. are'in the same: plane and: constitute: the: top surface: of the base structure M. This will enable. as.=will.hereinafter be explained; a: modified positioning. of the off-set sheave from its normal central position between the sheaves 21b; and; 2:lc, so astoreadily adapt the crowmbiockstructure for different stringing. arrangements: and for; different positions of 80' the anchorforthedead-line portionof thehoisti'ng: line; These changes may be: accomplished in the fleld'an'd; enables the use: of? my improved crown. block. arrangement under a. plurality of situations and: conditions, due to. its flexibility of adaptation By having the ofi-set sheavemountedsubstantially at the; center of? its associated: side: of the water table. the rust-nae will; be: wound on the drum. from acentral: position. and; hoisting: forces will be: symmetrically" applied: to the derrick. Also; cable: wear and: wear om cable: guides will be"materially decreased. The utilization of a cross-sheave in the manner: disclosed reduces fleet angle and contributes to the. efliciency of theoperaticm of the crowm block: and; likewise is effectivein reducing-z cable-iwear;

Reremng to Figs; 3 and Q of: the; drawings; we have illustratedithe. stringing: arrangement. of the hoisting line which. will. usually be: utilized with the" crown blo'ckx constituting. the. present. invention; In this diagrammatic illustration, the sheaves of the associated: traveliiigzblock; in: this case, five in number;.haveebeeniindicated respectivel'y'as 31421,. b, We, 3-121, and life; The. anchor for the-dead-lineend or the h'oisting'. line. orcable is indicated at. 32; and the: winding driumz. by: the numeralfli In bo'tlr of the'arrangements shown inFigs; 3 and- 4-, -the fast-line end portion is led from the winding over tlie-ciF-set sheavei'fl and is earnestness the middle sheavefl eof the traveling blocki nding' upon whether the anchor IJoint'is desired be disposed on the. right side as shown m ne." 3, or 'en the' left sideas shown in Fig; '4, the hoist line will be broug'ht up to-the sheavefleortlb, accordingly; As shown in Fig. 3; the hoistinglineis'carr-ie'd over the sheave 21 0, under 31c, cvefZld-i under 31d; and thence over the cross-over sheave 26, under sheave 3-1 a; over sheave Zia; under-sheave- 3th, and thence over the sheave 2 1 b'; whence-1t is led off to the anchor 32%; Nsimilararrangementis followed in' Fig'. 4, except tha-t the windingds reversedand the deadend line l'ed off fi'oim the sheave c tc the=anchor In both arrangements just described,.it will be seen'that the fast line and dead-end line portions are brought into innermost sheaves-of --the traveling block andcrown block, thus reducing tions with respect tothe side'upon which they. ,are disposed. More specifically, thev sheaves zla, 3la, 3), and 2H) rotate in one direction; whereas, sheaves 2 lc, 3lc,.2ld, and 3ld" rotate in an opposite'direction.

Modified stringing arrangements of the hoist-- ing line may be employed as shown in FigsjS-and 6 in order to bring out the dead-line todifferent anchor positions, asindicated at 32 and- 32. IIn this arrangementya, slightv modification"-in.'the

mounting of the oil-set. sheave is employed- .In-.

stead of having it mounted centrally between the sheaves 2H) and He, the off-set sheave is in this instance moved so as to be adjacent the sheave 2Ia or 2ld, depending upon whether it is desired to string the hoisting line from right to left as shown in Fig. 5, or from left to right as shown in Fig. 6.

In either case, the fast-line leads from the winding drum 33 over the off-set sheave 20 from whence it is carried under an outermost sheave of the traveling block and thence over and under the crown sheaves and traveling block sheaves successively, and is then carried from the traveling block sheave at the opposite end up over the cross-over sheave 26 to the anchor 32. It will be observed that in utilizing this stringing arrangement, the same crown block sheaves and traveling block are utilized as in the case of the Fig, 3

or Fig. 4 arrangement.

Where it may be desired to have an anchor as indicated at 32', the last sheave of the traveling block and the cross-over sheave 26 may be omitted and the dead-line carried directly from the last crown block sheave, namely, the sheave H01 in Fig. 5, or 2m in Fig. 6. While it has for purposes of illustration been indicated that the end sheave may be omitted in this case, it will be apparent that any one of the sheaves may be omitted, as long as four sheaves are utilized in the traveling block. Thus, if the middle sheave 3 is is omitted, it will give a symmetrical arrangement. Likewise, this arrangement will enable use of the crown block as described herein with a traveling block having four sheaves, in the event that a four-sheave block is the only one which is available in the field.

From the foregoing, it will be readily appreciated that the crown block of our invention is exceedingly flexible and readily adapted to various stringing arrangements and different locations which may be desired for the dead-line end anchor.

We claim as our invention:

1. A crown block assembly comprising a plu-' .6 opposite side of said first sheaves in such position that its extended axis of rotation will pass between said groups- 2.-A;crow,nyblock assembly comprising a plurality of sheaves supported for rotation in parallel-planes. andformed. into two spaced apart .groups, eachof which. contains the same number ofsheaveaan off-set sheave supported on one side-of said first sheaves in such position that its extended plane of rotation will pass betweensaid-groups, and a cross-over sheave sup- .portedon the oppositeside of said first sheaves in such position that its extended axis of rotation will pass between said groups.

33. A crown block comprising a group of sheaves mounted for rotation in uniformly spaced parallel planes, .one of said sheaves between the end sheaves ofsaid group being laterally off-set to bring a diametric side thereof into adjacent relationawith the corresponding diametrically opposite ,sidesof the other sheaves, and cross-over sheave means supported on the side of said group of sheaves opposite from said sheave which is offset.

.4. A crown block structure comprising a plurality of first sheaves supported in face to face relation, two of said sheaves being spaced apart a distance greater than the spacing between the remaining sheaves, an off-set sheave adjacent said first sheaves supported to have a plane of rotation parallel to said first sheaves and aligned with the space between said spaced apart sheaves, and cross-over sheave means supported with its plane of rotation at right angles to that of the other sheaves.

5. A crown block structure as defined in claim- 4, characterized by said oil-set sheave and crossover sheave being disposed on opposite sides of said common axis.

6. A crown block structure comprising a group of first sheaves supported for rotation about a common axis, an off-set sheave supported with its plane of rotation parallel to said first sheaves and between the ends of said group, and a crossover sheave supported with its plane of rotation at right angles to that of the other sheaves, said off-set sheave having a plane of rotation and said cross-over sheave an axis of rotation lying substantially in a common plane.

7. In combination, a traveling block having a set of sheaves supported with their planes of rotation parallel; a crown block comprising a set of sheaves supported with their planes of rotation parallel, an oiT-set sheave and a cross-over sheave having their planes of rotation disposed at right angles; and a hoisting line rove over the sheaves of said blocks, said line having one end leading off over said olT-set sheave and another end leading off over an inner sheave of said set of sheaves in the crown block.

8. In combination, a traveling block having a set of sheaves supported with their planes of rotation parallel; a crown block comprising a set of sheaves supported with their planes of rotation parallel, an oif-set sheave and a cross-over sheave having their planes of rotation disposed at right angles; and a hoisting line rove over the sheaves of said blocks, said line having a running end leading oil from an inner sheave of the traveling block over said off-set sheave, and an anchored end leading 01f over an inner sheave of said set of sheaves in the crown block. 7

9. A crown block assembly comprising a plurality of sheaves supported .for rotation in side by side relation and formed into two spaced apart s mian group's,v an off-set sheave supportedsonone side of said. first sheaves insuchposition that its e32 tended plane of rotation will" pass between groups, and a, cross-over sheave supported-ow the opposite side. of said first sheaves in such" position that its planeof? rotatiomwi-ll be relation tothe planesorrotation-of saidfirst sheaves.

1i0.- A crown block assembly comprising; in rality of sheaves supported for rotatinnir'isideby side relation and formed. into two groups-emails set sheave supported on one sideotfsaid sheaves in such position-that its extendedipiafle of rotation will pass between said?- aid.

cross-over sheave means disposed along: 'er-side'f saidfirst sheaves crossingrelatibm wthe'pll mes of rotation of said first sheaves.

11. A- crown block assembly comprising '9: p111 rality of sheaves supported for rotaltion imsiswhy side relation andformed imo ilwu grdupsganibfi set sheave supported on one side (if said met sheaves in such position that one side ot' its' p'eriphery will be disposed elo's tdthe plmie lifdwi-j sion between said groups, and cross-over sheave means disposed along a side of said first shewves in crossing relation to the piahsiof rotaitio'n of said first sheaves;

1%"- .In Mbinflibn; I wavering; blecls havin sheaveir 8119mm withtheis planes ofitmtation humiliate-61mm block comprising. set of sheaves supported in iece to face" relatiom. an? om-vset sheave on oneqsideof; sa-ida set and cross-over sheave meimsthe: ashes sideof saidset; and a 'hoisfin's line saveover the sheaves of said flocks; .saizihavingimie endileadiiigi oil over mi ses sheavie and weather and leading off stems-11am: sheave-0t said-set of sheaves;

HOWARD: D.

D; WALTERS REFERENGES- srrsn ,1- "rne rbnbwm reterehces are or real smin" the file-arms pitezit' Y i sums swims Pm "s 

